Sensitivity and specificity of arm circumference indicators in identifying malnourished children

Arm circumference indicators of nutritional status such as simple arm circumference, arm circumference-for-age and arm circumference-for-height have advantages for field use because of their simplicity and low cost. However, these indicators need to be evaluated in terms of their ability to identify children who are manourished by more accepted criteria such as weight-for-age and weight-for-height. This study used sensitivity-specificity analysis to evaluate arm circumference indicators in 3838 children 1 to 4 years of age in a rural area of El Salvador. It was found that simple arm circumference gave sensitivity-specificity results similar to arm circumference-for-age and generally better than arm circumference-for-height in identifying children with low weight-for-age. The three arm circumference indicators gave similar sensitivity-specificity results in identifying children with low weight-for-height. Linear correlations of the arm circumference indicators with weight-for-age and weight-for-height gave results which correspond to the results of sensitivity-specificity analysis, but the information obtained from correlations to was less useful in evaluating the adequacy of the individual arm circumference indicators for screening purposes. Sensitivity-specificity analysis is proposed as useful method for evaluating indicators for use in nutritional surveys and for screening for malnutrition.